Experiment with registered settings

lib/class-wp-rest-settings-controller.php

@@ -0,0 +1,156 @@
+<?php
+
+/**
+ * Manage a WordPress site's settings.
+ */
+
+class WP_REST_Settings_Controller extends WP_REST_Controller {
+	public function __construct() {
+		$this->namespace = 'wp/v2';
+		$this->rest_base = 'settings';
+	}
+
+	/**
+	 * Register the routes for the objects of the controller.
+	 */
+	public function register_routes() {
+		register_rest_route( $this->namespace, '/' . $this->rest_base, array(
+			array(
+				'methods'          => WP_REST_Server::READABLE,
+				'callback'         => array( $this, 'get_item' ),
+				'args'             => array(),
+				'permission_callback' => array( $this, 'get_item_permissions_check' ),
+			),
+			array(
+				'methods'          => WP_REST_Server::EDITABLE,
+				'callback'         => array( $this, 'update_item' ),
+				'args'             => $this->get_endpoint_args_for_item_schema( WP_REST_Server::EDITABLE ),
+				'permission_callback' => array( $this, 'get_item_permissions_check' ),
+			),
+			'schema' => array( $this, 'get_public_item_schema' ),
+		) );
+	}
+
+	public function get_item_permissions_check( $request ) {
+		return current_user_can( 'manage_options' );
+	}
+
+	/**
+	 * Get the settings.
+	 *
+	 * @param WP_REST_Request $request Full details about the request.
+	 * @return WP_Error|array
+	 */
+	public function get_item( $request ) {
+		$options  = $this->get_registered_options();
+		$response = array();
+
+		foreach ( $options as $name => $args ) {
+			// default to a null value as "null" in the response means "not set"
+			$response[ $name ] = get_option( $args['option_name'], $args['schema']['default'] );
+
+			// because get_option() is lossy, we have to
+			// cast values to the type they are registered with.
+			switch ( $args['schema']['type'] ) {
+				case 'string':
+					$response[ $name ] = strval( $response[ $name ] );
+					break;
+				case 'number':
+					$response[ $name ] = floatval( $response[ $name ] );
+					break;
+				case 'boolean':
+					$response[ $name ] = (bool) $response[ $name ];
+					break;
+			}
+		}
+
+		return $response;
+	}
+
+	/**
+	 * Update settings for the settings object.
+	 *
+	 * @param  WP_REST_Request $request Full detail about the request.
+	 * @return WP_Error|array
+	 */
+	public function update_item( $request ) {
+		$options  = $this->get_registered_options();
+		$params = $request->get_params();
+
+		foreach ( $options as $name => $args ) {
+			if ( array_key_exists( $name, $params ) ) {
+				// a null value means reset the option, which is essentially deleting it
+				// from the database and then relying on the default value.
+				if ( is_null( $request[ $name ] ) ) {
+					delete_option( $args['option_name'] );
+				} else {
+					update_option( $args['option_name'], $request[ $name ] );
+				}
+			}
+		}
+
+		return $this->get_item( $request );
+	}
+
+	/**
+	 * Get all the registered options for the Settings API
+	 *
+	 * @return array
+	 */
+	protected function get_registered_options() {
+		require_once ABSPATH . 'wp-admin/includes/plugin.php';
+		$rest_options = array();
+
+		foreach ( get_registered_settings() as $name => $args ) {
+			if ( empty( $args['show_in_rest'] ) ) {
+				continue;
+			}
+
+			$rest_args = array();
+			if ( is_array( $args['show_in_rest'] ) ) {
+				$rest_args = $args['show_in_rest'];
+			}
+
+			$rest_args = array_merge( $rest_args, array(
+				'option_name' => $name,
+				'name'        => ! empty( $rest_args['name'] ) ? $rest_args['name'] : $name,
+				'schema'      => array(
+					'type'    => empty( $args['type'] ) ? null : $args['type'],
+					'description' => empty( $args['description'] ) ? '' : $args['description'],
+					'default'     => isset( $args['default'] ) ? $args['default'] : null,
+				),
+			));
+
+			// skip over settings that don't have a defined type in the schema
+			if ( empty( $rest_args['schema']['type'] ) ) {
+				continue;
+			}
+
+			$rest_options[ $rest_args['name'] ] = $rest_args;
+		}
+
+		return $rest_options;
+	}
+
+	/**
+	 * Get the site setting schema, conforming to JSON Schema.
+	 *
+	 * @return array
+	 */
+	public function get_item_schema() {
+		$options = $this->get_registered_options();
+
+		$schema = array(
+			'$schema'    => 'http://json-schema.org/draft-04/schema#',
+			'title'      => 'settings',
+			'type'       => 'object',
+			'properties' => array(),
+		);
+
+		foreach ( $options as $option_name => $option ) {
+			$schema['properties'][ $option_name ] = $option['schema'];
+		}
+
+		return $this->add_additional_fields_schema( $schema );
+	}
+}